1. Field of the Invention
The present invention relates to a tool suitable for breaking loose the foreign material wedged between the gate box lid and the gate box and foreign material wedged into the recesses on the gate box lid, grabbing hold and lifting of the gate box lid, and the removal and replacement of the gate box lid.
2. Description of Prior Art
It is well known that city water shut-off valves are positioned below ground level. Access to these shut-off valves is achieved by use of a key inserted through an entrance hole at ground level and down a vertical extending access conduit. This access conduit is usually a cylindrical pipe having an approximate 8" diameter. Such access conduits are commonly called "gate boxes".
The access conduit entrance is invariably provided with a cover (the gate box lid). For safety, security and durability, this lid is usually fabricated from a rigid material such as cast iron. The lid has a depth of approximately 3 7/16".
Primarily to prevent rainwater and dirt from entering the access conduit, the gate box lids do not have any holes that go all the way through them. Instead, they are formed with recesses in their top surface at 180.degree. intervals on the top, outer circumferential edge of the lid.
One technique that has been tried for lifting and removing the gate box lids is a pair of tongs which are inserted into the two recesses. This relies on a tight grip by the operator as the jaws on the tongs are not fitted for the recesses. The tongs provide no means of breaking the seal around the lid or for extracting foreign material from the gate box lid recesses.
Another technique that has been tried for lifting or maneuvering these lids include the use of crow bars (or similar rod-like tools) which are inserted into one of the recesses on the lid. This relies on friction between the lid and the tool to affect the lifting of the lid. There is very little control over the movement of the lid, and there is a significant risk of injury to the operator.
Art has been designed suitable for the lifting or removal of manhole covers, which are larger, heavier and having less proportional depth. See e.g. U.S. Pat. Nos. 4,650,232 and 4,482,182. Art has been designed for percussion type tools suitable for box openers and chisels. See e.g. U.S. Pat. Nos. 103,330 and 2,475,041.